The present invention relates to battery chargers, and in particular, to battery charging systems and methods with adjustable current limiting.
Batteries have long been used as a source of power for mobile electronic devices. Batteries provide energy in the form of electric currents and voltages that allow circuits to operate. However, the amount of energy stored in a battery, is limited, and batteries lose power when the electronic devices are in use. When a battery's energy supply becomes depleted, the battery's voltage will start to fall from its rated voltage, and the electronic device relying on the battery for power will no longer operate properly. Such thresholds will be different for different types of electronic devices.
Many types of batteries are designed for a single use. Such batteries are discarded after the charge is depleted. However, some batteries are designed to be rechargeable. Rechargeable batteries typically require some form of battery charging system. Typical battery charging systems transfer power from a power source, such as an AC wall plug, into the battery. The recharging process typically includes processing and conditioning voltages and currents from the power source so that the voltages and currents supplied to the battery meet the particular battery's charging specifications. For example, if the voltages or currents supplied to the battery are too large, the battery can be damaged or even explode. On the other hand, if the voltages or currents supplied to the battery are too small, the charging process can be very, inefficient or altogether ineffective. Inefficient use of the battery's charging specification can lead to very long charging times, for example. Additionally. If the charging process is not carried out efficiently, the battery's cell capacity (i.e., the amount of energy the battery can hold may not be optimized.
The type of power source is another important aspect of battery charging. For example, some power sources may provide AC voltages and currents, and other power sources may provide DC voltages and currents. One problem associated with charging a battery pertains to transforming the voltages and currents available at the power source into voltages and currents that may be used to charge a battery. Existing battery chargers are typically static systems. Battery charger circuits are typically hardwired to receive power from a particular source and provide voltages and currents to a particular battery based on the battery's charge specification. However, the inflexibility of existing chargers results in many of the inefficiencies and problems described above. It would be very advantageous to have battery charging systems and methods that were more flexible than existing systems or even adaptable to particular battery technologies, or the changing battery charging environment.
Thus, there is a need for improved battery charger systems and methods that improve the battery charging process. The present invention solves these and other problems by providing battery charging system and methods with adjustable current limit.